Most soldering and desoldering tools (also referred to as devices) currently on the market incorporate some means for monitoring, controlling or regulating the temperature of the soldering or desoldering tip of the device. Ultimately each type of device coordinates the temperature of the heated tool tip with means for regulating the current provided to the tool heating element. Such devices can often take one of two forms.
The first employs a "temperature sensitive" thermal or thermomagnetic switch which turns current to the heating element on and off. In such devices, changes in the temperature of the heated tool tip are translated into mechanical actuation of a switch which controls power provided to the heating element.
The second type of device incorporates a temperature sensor which monitors the temperature of the heated tool tip. The sensors take many forms, such as resistance temperature detectors, thermistors and thermocouples. Sensors often are located in close proximity to the heated tip in order to closely monitor tip temperature. In certain embodiments, the sensor is positioned within a hollow bore inside the tip and is electrically connected to control elements located in the body or handle of the device, which regulate the heating elements of the device, to alter temperature at the operating tip.
Devices employing a temperature sensor have, for most applications, generally proven superior to devices relying on simple switches. However, even the more sophisticated sensor devices have also exhibited certain disadvantages. For example, the temperature sensors can wear out or become damaged during prolonged use. Replacement of the sensors is in many instances relatively difficult and costly. Sensors currently employed are usually "hard-wired" to other components in the device and thus require that the device be disassembled for replacement. Replacement may also require replacement of leads or resoldering of connections resulting in significant downtime as a result of the tool being out of commission, especially when these operations are performed by electrically unskilled operators. Also, the sensors are often integrated with other components within the device such that replacement of the sensor requires concomitant replacement of other components which still have useful life. It would, therefore, be desirable to provide a device which provides the advantage of a temperature sensor while providing for easier and more economic sensor replacement and operation.